Nucleotides released by smooth muscle cells (SMCs) and by innervating nerve terminals activate specific P2 receptors and modulate bladder contraction. We hypothesized that cell surface enzymes regulate SMC contraction in mice bladder by controlling the concentration of nucleotides. We showed by immunohistochemistry, enzymatic histochemistry, and biochemical activities that nucleoside triphosphate diphosphohydrolase-1 (NTPDase1) and ecto-5′-nucleotidase were the major ectonucleotidases expressed by SMCs in the bladder. RT-qPCR revealed that, among the nucleotide receptors, there was higher expression of P2X1, P2Y₁, and P2Y₆ receptors. Ex vivo, nucleotides induced a more potent contraction of bladder strips isolated from NTPDase1 deficient (Entpd1^−/−) mice compared to wild type controls. The strongest responses were obtained with uridine 5′-triphosphate (UTP) and uridine 5′-diphosphate (UDP), suggesting the involvement of P2Y₆ receptors, which was confirmed with P2ry6^−/− bladder strips. Interestingly, this response was reduced in female bladders. Our results also suggest the participation of P2X1, P2Y₂ and/or P2Y₄, and P2Y₁₂ in these contractions. A reduced response to the thromboxane analogue U46619 was also observed in wild type, Entpd1^−/−, and P2ry6^−/− female bladders showing another difference due to sex. In summary, NTPDase1 modulates the activation of nucleotide receptors in mouse bladder SMCs, and contractions induced by P2Y₆ receptor activation were weaker in female bladders.

The emergence of purinergic signaling has given ATP and other extracellular nucleotides a whole new perspective. This concept refers to the fact that extracellular nucleotides released by most cells act as signaling molecules via specific membrane receptors called purinergic receptors, thus regulating several cellular functions. Although purinergic signaling has been well studied in several physiological systems, recent work has shown that this signaling pathway is also essential in the immune system. In this review, we will discuss the complex role of purinergic signaling in the regulation of effector T cell functions, including migration, differentiation, and activation. We will also cover the role of P2 receptors in the development of autoimmune diseases. Understanding how P2 receptors regulate effector T cells will likely further our understanding of protective immunity and immune pathogenesis and may lead to new therapeutic approaches and agents in immune diseases

We have generated polyclonal and monoclonal antibodies by genetic immunization over the last two decades. In this paper, we present our most successful methodology acquired over these years and present the animals in which we obtained the highest rates of success. The technique presented is convenient, easy, affordable, and generates antibodies against mammalian proteins in their native form. This protocol requires neither expensive equipment, such as a gene gun, nor sophisticated techniques such as the conjugation of gold microspheres, electroporation, or surgery to inject in lymph nodes. The protocol presented uses simply the purified plasmid expressing the protein of interest under a strong promoter, which is injected at intramuscular and intradermal sites. This technique was tested in five species. Guinea pigs were the animals of choice for the production of polyclonal antibodies. Monoclonal antibodies could be generated in mice by giving, as a last injection, a suspension of transfected cells. The antibodies detected their antigens in their native forms. They were highly specific with very low non-specific background levels, as assessed by immune-blots, immunocytochemistry, immunohistochemistry and flow cytometry. We present herein a detailed and simple procedure to successfully raise specific antibodies against native proteins.

The emergence of purinergic signaling has given ATP and extracellular nucleotides a whole new perspective. This concept refers to the fact that extracellular nucleotides released by most cells act as signaling molecules via specific membrane receptors called purinergic receptors, thus regulating several cellular functions. Although purinergic signaling has been well studied in several physiological systems, recent work has shown that this signaling pathway is also essential in the immune system. In this minireview, we will discuss the complex role of purinergic signaling in the regulation of effector T cell functions, including migration, differentiation, and activation. We will also cover the role of P2 receptors in the development of autoimmune diseases. Un-derstanding how P2 receptors regulate effector T cells will likely further our under-standing of protective immunity and immune pathogenesis and may lead to new therapeutic approaches and agents in immune diseases